Dendritic spines and development: towards a unifying model of spinogenesis--a present day review of Cajal's histological slides and drawings.

García-López P, García-Marín V, Freire M - Neural Plast. (2011)

Bottom Line:
Hence, the cellular and molecular mechanisms underlying their generation and plasticity, both during development and in adulthood, are a matter of fundamental and practical interest.Indeed, a better understanding of these mechanisms should provide clues to the development of novel clinical therapies.Based on the data available in the literature regarding the formation of dendritic spines during development and our results, we propose a unifying model for dendritic spine development.

ABSTRACTDendritic spines receive the majority of excitatory connections in the central nervous system, and, thus, they are key structures in the regulation of neural activity. Hence, the cellular and molecular mechanisms underlying their generation and plasticity, both during development and in adulthood, are a matter of fundamental and practical interest. Indeed, a better understanding of these mechanisms should provide clues to the development of novel clinical therapies. Here, we present original results obtained from high-quality images of Cajal's histological preparations, stored at the Cajal Museum (Instituto Cajal, CSIC), obtained using extended focus imaging, three-dimensional reconstruction, and rendering. Based on the data available in the literature regarding the formation of dendritic spines during development and our results, we propose a unifying model for dendritic spine development.

Mentions:
Nevertheless, in normal animals, Purkinje cell branchlets give rise to long spine-like processes that form synaptic contacts with parallel fibers [15]. Following the onset of these synaptic contacts, the long spine-like processes develops a terminal head, and the parallel fibers form axonal swellings that contain synaptic vesicles. The mature dendritic spine has a big terminal head and a short neck (Figure 4(a)). Cajal [23] described similar long spine-like processes in the Purkinje cell branchlets impregnated by the Golgi method of the 15-day-old cat (Figure 10(b)). Larramendi [15] also found that parallel fibers often form long synaptic adhesions with developing spines (Figure 4(b)). These asymmetric synapses become shorter as the dendritic spine reaches maturity through a phenomenon referred to as “synaptic adhesion waning” by Larramendi [15].

Mentions:
Nevertheless, in normal animals, Purkinje cell branchlets give rise to long spine-like processes that form synaptic contacts with parallel fibers [15]. Following the onset of these synaptic contacts, the long spine-like processes develops a terminal head, and the parallel fibers form axonal swellings that contain synaptic vesicles. The mature dendritic spine has a big terminal head and a short neck (Figure 4(a)). Cajal [23] described similar long spine-like processes in the Purkinje cell branchlets impregnated by the Golgi method of the 15-day-old cat (Figure 10(b)). Larramendi [15] also found that parallel fibers often form long synaptic adhesions with developing spines (Figure 4(b)). These asymmetric synapses become shorter as the dendritic spine reaches maturity through a phenomenon referred to as “synaptic adhesion waning” by Larramendi [15].

Bottom Line:
Hence, the cellular and molecular mechanisms underlying their generation and plasticity, both during development and in adulthood, are a matter of fundamental and practical interest.Indeed, a better understanding of these mechanisms should provide clues to the development of novel clinical therapies.Based on the data available in the literature regarding the formation of dendritic spines during development and our results, we propose a unifying model for dendritic spine development.

ABSTRACTDendritic spines receive the majority of excitatory connections in the central nervous system, and, thus, they are key structures in the regulation of neural activity. Hence, the cellular and molecular mechanisms underlying their generation and plasticity, both during development and in adulthood, are a matter of fundamental and practical interest. Indeed, a better understanding of these mechanisms should provide clues to the development of novel clinical therapies. Here, we present original results obtained from high-quality images of Cajal's histological preparations, stored at the Cajal Museum (Instituto Cajal, CSIC), obtained using extended focus imaging, three-dimensional reconstruction, and rendering. Based on the data available in the literature regarding the formation of dendritic spines during development and our results, we propose a unifying model for dendritic spine development.